If a police officer turns up at your front door demanding to search your premises, the first thing any British citizen should ask the officer in blue is whether he or she has a warrant. If they don't, they should go away.

On Wednesday, following the Queen's speech, the Damian Green affair took a new turn when the Speaker revealed that Parliament's top security officer, serjeant at arms Jill Pay, never asked whether they had a search warrant to raid the MP's office.

This information is breathtaking for two reasons. It shows that the Commons authorities were completely supine in their attitude towards a police request that rode roughshod over rights won by centuries of parliamentarians to guard their liberties. It also suggests that the Metropolitan police seem to have little regard themselves for the niceties of the law of the land, where even the humblest tenant in the most squalid house can expect to see a search warrant before the police rummage through his or her personal possessions.

These do not seem to be the actions of a police force whose independence and professionalism was praised by Jacqui Smith, the home secretary, a few days ago.

On top of this, it appears Jill Pay never consulted the Clerk of the House, Dr Malcolm Jack, the equivalent of Parliament's chief executive, who would have known immediately that something might be wrong.

The Speaker, Michael Martin, does not come out of this well. He seems something of a Pontius Pilate, a man who was given only the barest of all details of what was going on and was not sufficiently curious for more. Above all, he did not ask the vital question: whether the police had a warrant. It is all very well raging about the way the police handled this search, yet he never took any steps to stop them.

The treatment of Damian Green by the police has – as both David Cameron and David Blunkett have said – been heavy-handed and ill-considered. Even given the substance of the issue – the police investigation into the leak of information from the private office of the home secretary – this still seems to be over the top. None of the leaks that became public affected national security. All of them exposed failings by the Home Office. The worst allegation I have heard from Whitehall is that the civil servant did have access to classified information which could have affected national security; there is no evidence that any of this information was passed to Damian Green or leaked to the press.

The latest disclosures now make everything worse. Generations of parliamentarians have fought to safeguard the liberties of the House of Commons – on the grounds that they protect the rights of the people. They should not be lightly thrown away at the behest of the Metropolitan police one Thursday afternoon when MPs were on holiday. Heads should roll over this.